lecture 11 Flashcards
(15 cards)
Define autoimmunity
Autoimmunity; immune system doesn’t attack its own cells and tissue, it cannot self distinguish self ag from non-self ag
normally potentially self-reactive lymphocytes are destroyed by they escape this process and enter lymphoid organs
immune system
responds to self ag via self-active T and B lymphocytes
if there is no signal for the T cell it will become unresponsive
Explain the mechanism of autoimmunity
mechanism of autoimmunity
autoimmunity is effected by age, gender etc.
its characterised by tissue damage is a result of hypersensitivity reactions, tissues are damaged by auto reactive T cells or abs
genetic factors and infection and environment exposure -> immune regulation-> autoimmunity
For autoimmune diseases explain how pathogenesis is achieved, list the 3 ways
autoimmune disease pathogenesis
- hidden ag; some ag can hide in tissue when this tissue is damaged and these ag are released they are recognised as non self and the immune system kills it
- mimcry, abs react to microbial ag crocc react with host protein
- failure of normal regulatory mechanisms like apoptosis, so reactive lymphocytes are not deleted as cells develop in thymus.
List autoimmune diseases associated with the following organs endocrine system skin blood cells neurological system kidneys eyes skeletal and heart muscles reproductive system systemic
endocrine system; thyroid, pancreas, adrenals
-the skin; hair follicle disease, blistering diseases
-Blood cells; immune mediated haemolytic anaemia
-neurological system; degernative myelopathy
- Kidneys -nephritis
-eyes uveitis
-skeletal and heart muscle- cardiomyopathy
reproductive system abs to sperm
some are systemic arthritis
For autoimmune hypothyroiditis explain the effect on hormones what occurs when clinical signs occur clinical signs diagnostic tests.
Thyroid gland is not incorporating iodine into the hormones T3 and T4
it occurs when Ab in the blood or tissue start to attack the thyroid gland, thus affecting the amount of T3 and T4 produced
signs are delayed
signs include greasy regrowth, easy weight gain
diagnostic test thyroid hormone, anti thyroglobulin ab tests
List some signs of immune deficiency
some signs of immune deficiency
disease occurring in young littermate animals with one shortly after expected time of loss of maternally derived immunity.
chronic recurrent infection
infection in multiple body sites
persistent lymphopaenia (low levels of lymphocytes)
List the types of immune deficiencies
types of immune deficiencies
- primary immune deficiencies
- secondary immune deficiencies
What are DNA defects
DNA defects primary immune deficiency deficiencies of innate immunity eg. complement deficiencies or deficiencies of adaptive immunity
List the different deficiencies of adaptive immunity for DNA defects
deficiencies of adaptive immunity for DNA defects
- humoral immunodeficiencies- body can’t make enough ab to fight the infection
- cellular (T cell) immunodeficiencies- cellular defences against infection fail to work
- combined immunodeficiencies - both B and T cells defects
- primary immune deficiency
Explain how defects in neutrophils getting into tissues is possible
Defects in neutrophils getting into tissues
deficiency of innate immunity
defects entry into inflamed tissues
-mutation prevents WBC from adhering to vascular endothelium preventing them from leaving blood vessels and eliminating harmful bacteria and viruses, without adhesion molecules (integrins) this stops leucocytes from getting to inflamed tissues
What is recycle congenial neutropenia and give an example
cyclical or serve congenital neutropenia (low levels of neutrophils);
cyclic fluctuation in no. of blood cells, no. of neutrophils (WBC) decreases rapidly and returns to normal
stem cell growth factor s defects
episodes of infections
-grey collie syndrome
For defects of the adaptive immune system explain what occurs to individuals with deficiencies with T cells, B cells and CD4 or 8 or both
deficiencies in T, B cells and CD 4/8 T cells or both
Individual with T cell deficiencies= die from viral infection
individuals with B cell deficiencies= die from bacterial infection
deficiencies in CD4 or 8 T cells or both = shit ab production
Discuss immune deficiency in horses in-particular severe combined immunodeficiency and Ig deficiencies
Immune deficiency in horses
appear early in life
primary immune deficiencies are rare
-severe combined immunodeficiency
failure to produce functional T and B cells
Agammaglobulinaemia ( no ab, igM disapears)
pneumonia is the most common symptom
-Ig deficiency
Agammaglobulinaemia no B cells, normal T cell response
-igM deficiency
What occurs for Immunosenescence
Immunosenescence
age related decline in immune function in older animals
decrease in circulating CD4 T cells
T cell function decreases
fewer naive cells leaving the bone marrow
all of this leads to increased susceptibility and autoimmunity and neoplasia
Discuss immunosuppression (types)
Immunosuppression
-medical immunosuppression
used for autoimmune diseases; chemotherapy for cancer
glucocorticoids- anti-inflammatory and immunosupressressive
cytotoxic drugs; inhibit cell division by blocking nucleic acid synthesis (cancer chemotherapy)
-Virus induced immunosuppression
loss of lymphocytes in viral infections
for canine distemper virus
the entry receptors is on T and B cells, it then enters the blood stream killing T and B cells-> lymphopaenia, it then invades the spleen, lymph nodes, MALT, bone marrow, thymus and brain, there is a suppression of IL1 and 2, a failure to make ab.
